Machine Type Communication (MTC) User Equipment (UE) (or user terminal or terminal), also referred to as Machine to Machine (M2M) user communication device, is currently a main form of application of Internet of Things (IoT). In the 3rd Generation Partnership Project (3GPP) Technical Report (TR) 45.820 V200, several techniques suitable for Cellular IoT (C-IoT) are disclosed, among which a Narrow-Band Long Term Evolution (NB-LTE) is a most attractive one. The bandwidth of the system is 200 KHz, which is the same as the channel bandwidth of Global System for Mobile communication (GSM) system. This is advantageous for the NB-LTE system to reuse the spectra of the GSM system and reduce interference with neighboring GSM channels. The NB-LTE has a transmission bandwidth of 180 KHz and a downlink sub-carrier spacing of 15 KHz, which are the same as the bandwidth of one Physical Resource Block (PRB) and sub-carrier spacing of the Long Term Evolution (LTE) system. For such narrow band system, the design of Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS), occupying six PRBs in the current LTE system, is no longer suitable and a new design of PSS/SSS is thus needed.
In the related art, there is currently no feasible solution to the problem associated with inappropriate design of the synchronization signals in the NB-LTE system.